Real-world use of JavaScript Symbols and class expressions in Lightning Web Components

gistfile1.txt

    // Code from Lightning Web Components source, taken from Chrome dev console
    const Navigate = Symbol("Navigate");
    const GenerateUrl = Symbol("GenerateUrl");
    const NavigationMixin = Base => {
      assertIsLightningElementSubclass(Base);
      return class extends Base {
        [Navigate](pageReference, replace) {
          navigationService.getService(this).navigateTo(pageReference, {
            replace
          });
        }

        [GenerateUrl](pageReference) {
          return navigationService.getService(this).generateUrl(pageReference);
        }

      };
    };
    NavigationMixin.Navigate = Navigate;
    NavigationMixin.GenerateUrl = GenerateUrl;
    // ...
    exports.NavigationMixin = NavigationMixin;

    // Used in client Code
    export default class BoatDetailTabs extends NavigationMixin(LightningElement) {

    // ...
    // Navigates to record page
    navigateToRecordViewPage() { 
        event.preventDefault();
        this[NavigationMixin.Navigate]({
            type: 'standard__recordPage',
            attributes: {
                recordId: this.boatId,
                objectApiName: 'Boat__c',
                actionName: 'view'
            }
        });
    }